Quality of engineering and construction are the reasons two of us have recommended that you look at Northstar. There are several other brands for well made campers but many of them are very heavy and have multiple slides. I would not buy a Lance. You want a unit that will handle all the jolts and swaying that occur with years of use.
I also really like the Northstar cassette toilets. That fits the way I travel in remote areas where dump stations are rare or nonexistent. Also check the propane for the WC. I believe it only has one tank. That could be very inconvenient. My Northstar mattress is a standard Queen. I appreciate the full length and upgrading to a residential foam mattress was easy and inexpensive.